Ton of variables. Could be a half day, could be a couple. Depends on how hard the paint is, your skill level, what you are using, etc. Looks like it will require compounding to remove the swirls and polishing to remove any hazing or marring the compounding step leaves behind. If you don't have a good DA polisher, you will need one, along with a good compound, cutting pads, polishes (maybe 2) with polishing and finishing pads.